This invention relates to internal combustion engines and more particularly to an improvement in valve mechanism to direct intake and exhaust flow in and out of the engine.
Poppet type valves are most widely used valves to open and close combustion chamber. A conventional engine uses at least two individual poppet valves, one for the intake and another for exhaust, to control the engine gas exchange process. They operate in timed relation to the rotation of the engine crank shaft. Other types of valves such as rotary or sleeve valves, and in some instance a single poppet valve is also used to control the flow. There are advantages and disadvantages with any of these systems. Obtaining a positive sealing for the rotary and sleeve type valve for different speed range is still a challenge. Poppet type valves ensure positive sealing, however when individual poppet valve is used for intake and exhaust, it reduces the size of the gas passage, increases weight, and requires more energy to drive, to name a few. The use of single poppet valve is advantageous from the aspect of lightness and simplicity of construction, valve temperature control, and combustion chamber design.
The idea of an internal combustion engine having a single poppet type valve to control intake and exhaust flow of the combustion chamber is very well recognized. It dates back to as early as Jun. 16, 1895, U.S. Pat. No. 5,428,46 to Diesel, to the present time Pub. Date. Jul. 7, 2011, Pub. No. US2011/0162607 A1 to Joel et al. Most of these inventions are adaptable for use under constant speed condition where it is not necessary to control the intake and exhaust flow and timing in relation to the speed change. A few of the inventions, such as U.S. Pat. No. 2,107,389 and U.S. Pat. No. 40,755,986, provide mechanics to control the intake and exhaust flow before they enter the combustion chamber through the poppet valve. However, the intake timing and the size of gas flow passage directly depends on the timing and the size of the exhaust, hindering the optimization of valve timing. There are other limiting factors of single poppet type valve, such as the placement of the spark plug and the fuel injector system using conventional poppet type valves.
It is therefore an object of the invention to provide a combination of poppet type and unique plate type of valve system to minimize drawbacks of a current valve system and improve upon it.
Another object of our invention is to provide scavenging of the intake flow and simultaneously provide cooling of the poppet valve and the exhaust means, employing a common air chamber.
A further object of our invention is to provide a poppet type valve engine which is mechanically similar to standard practice and thus variable valve timing can be employed.
It is a general object of the present invention to improve internal combustion engine design.